Balancing machine



Sept- 17, 1929 w. E. TRUMPLER 1,728,518

BALANCING MACHINE 7 y W//liam E. Pump/ff.

f 'f .I ATTORNEY Sept 17, 1929' w. E. TRUMPLER 1,728,518

BALANC-ING MACHINE Filed Aug. 28, 1925 5 Sheets-Sheet 2 WITNESSES: INVENTOR w/y//b/Z 5mm/m. f MW sept. 17, 1929.

Filed Aug. 28, 1925 W. E. TRUMPLER BALANCING MACHINE 3 Sheets-Sheet 3 24 23 Fei-4 4 Y y Z5 `5` WITNESSES: 2

I l INVENTOR W////am E'. Pump/af,

BY (zA/V ATTORNEY Patented Sept. 17, 1929 UNITED STATES PATENT OFFICE WILLIAM E. TBUMPLEB, OF WILKINSBURG, PENN SYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC MANUFACTURING COMPANY, A CORPORATION 0F PENNSYL- VANIA.

BALANCING MACHINE Application led August 28, 1925. Serial No. 53,116.

My invention relates to balancing machines, more particularly to dynamic balancing machines for detecting parasitic masses in rotating bodies, such as rotors and the like.

It is among the objects of my inventiop to provide a balancing machine of simple, compact and durable mechanical construction which shall 'comprise a minimum number otoperating parts and which shall be particularly adapted for balancing or testing imbalance in rotors manufactured in production quantities, with a minimumof expense.

Another object of my invention is to provide a balancing machine in which the oscillatable bed member is supported upon leaf spring elements .of such type as restrain the bed member against oscillatory movement in a vertical direction aswell as radial movement from the axis of oscillation, and in 2o which the spring elements are designed to be arranged in such manner that their planes of symmetry extending parallel to the faces of the springs intersect at a line constituting the axis about which the bed member oscillates.

Heretofore, balancing machines commonly utilized spring elements of the coil-shape type, which were conducive to vertical oscil- [ations resulting from the impulses set upby 80 the parasitic masses in the rotatn body that was journalled on the bed -mem er. With this type of spring mounting it was ditlicult to provide proper driving facilities for the rotor that was mounted on the bed member,

since no. adequate vdriving connections to a 'prime mover could be provided unless the latter were mounted uponthe bed'itself. This is an undesirable condition for many reasons, the principal one of which is the accumula- 40 tion of an excessive mass on the bed member, which detracts from its sensitiveness to the impulses of the unbalanced masses acting upon it.

My present invention contemplates the provision .of a sprin action that provides freedom of motion o the bed member in an angular direction about a vertical'axis, by means of which the bed member will oscillate in a horizontal plane, and with this arrangement it is a simple matter to provlde of my invention,

driving connections between the rotor to be tested and a prime mover, as by the usual belt drive.

'.lfthis structure lends itself to simplicity in deslgn, and permits rugged mechanical lconstruction, thus assuring a stable balancing. element that retains its initial adjustment under severe operating conditions.

In practicing my invention, I employ a stationary base member adapted to support a 60 bedthat is provided with pedestals for rotatably mounting a rotor to be tested. I utilize a plurality of at spring elements, which are disposed intermediate the base and bed member and which are mounted in a manner to provide relative angular adjustment of the faces of the springs. The purpose of adjusting the spring elements is to change the local tion of the axis of oscillation with respect to any transverse plane of the rotor to be tested,

for the purpose of ascertaining the degree of unbalance in any two transverse planes of such rotor, in accordance with a familiar practice.

In the accompanying drawings, constituting a part hereof and in which like reference characters designate like parts,

Figure 1 is a view in side elevation of a balancing machine embodying the principles Fig. 2 is a plan view thereof, v

Fig. 3 is a view, partially in ,section and partially in end lelevation, of the balancing machine shown in Figs. 1 and 2,

Fig. 4 is a view partially in section and 85 partially in elevation of one of the spring supporting members embodied in the balancing machine, and

Fig. 5 is 'a sectional view/ of the supporting member taken on the line V--V ofFig. 4.

Referring to the drawings, the apparatus therein illustrated comprises na base member 1, which is adapted to bersecured to a suitable foundation, a bed member 2, adapted to be supported by said base member, a plurality of standards or pedestals '3 that are mounted on the base 1 and adapted t receive vertically disposed flat spring elements 4, which serve to support the bed member 2, and a pair of pedestal journal bearings 5, which to rotatably journal a rot are secured to the bed member 2 and adapted 6 to be tested. A dial or other suitable indicator 7 is mounted upon the base 1 in such manner that its contact member 8 engages a portion of the bed member 2, by means of the usual bell crank connection so that any oscillatory motiorli of the latter will be registered by the A pulley 9 of relatively wide face isjournalled atone side to the frame of the base 1, by means of a shaft 10 having a cone pulley 11 mounted on one end thereof. 1A motor 12, having a cone pulley 13 secured on its extended shaft portion, is mounted in 'working alinement with the pulley 11, and a drive Abelt 14 connects the pulleys 11 and 13 to 'transmit motion from the motor to the shaftlO; A drive belt l15 is disposed around the pulley 9 and the rotor 6 that is j ournalled on the bed member 2. The belt member 15 constitutes an endless lbelt that traverses a pair of tension wheels 16, which are rotatably mountedl upon the frame of thebase land are held against the belt 15 by the gravity eect of ad( weight 17 that is secured by a bolt 18 in a guide slot 19 of a vertical bracket 20 that is fastened to the base 1. The belt also passes over an idler pulley 21 that is secured to the base 1 in alinement with. the pulley 9 on the opposite side of the base frame.

In order that the bed member 2 may be permittedto oscillate in a horizontal plane, the at springs 4 are disposed within the pedestals 3 in such manner that they may be turned about their longitudinal axes to cause their planes of symmetry to intersect in a vertical oscillation axis 22.

As shown in Figs. '3 and4 the springs 4 are provided at their ends with cylindrical portlons 23 by means of which they are rotatably mounted within the pedestals 3 and likewise are disposed to rotatably engage cylindrical recesses 24 in the lower surface of the bed member 2. y

In order that the springs may be turned readily while the bed' member 2 is loaded with a rotor 6, the end portions 23 ofthe springs 4 are provided with cup like depressions 25 which engage steel balls 26 that bear upon corresponding cu like depressions 27 in the bottom of the pe estals 3 and the cylindrical recesses-24, respectively. g

- When it is desired to position the oscillation axis 22, the springs 4I may be turned by means of a suitable wrench'within the pedestals 3 in such .manner that their planes of symmet parallel to their fiat faces intersect in a pre etermined common vertical lineor' oscillation axis 22, as best shown in Fig. 2.

' The rictional' resistance betweenthe cylin- 'drical end portions 23 of the `springs4 and the edestals 3`is s ulcient to prevent them from ecoming, accidentally misaligned when the balancing machine is in operation.

Vto position the axis of. oscillation in any predetermined vertical line, however, itis nerally desirable to conline the axis of oscillation tosome position along the axis of rotation of the rotor 6 to be tested. With such disposition of the spring elements, the bed member is restrained against movement in any plane excepting angular movement around the oscillation axis 22, the line of intersection of the planes of the spring leaves, this movement occurring in a horizontal plane. This oscillation axis -is first brought into one of the two transverse correcting lanes of the rotor to be balanced. Since it 1s desirable for accurate balancing to make corrections in at least two of such transverse planes, it will be necessary to adjust the spring elements for two corresponding positions, the planes chosen being preferably the end faces ofthe rotor, where correction for. unbalance is most readily rformed, as-by the removal or addition o correction weights, which is customary in practice.

The operation'o my device is similar to that of other well-known balancing machines,

in that the rotor mounted on the movable bed is rotated at a suitable speed through the belt drive mechanism, by the motor 12. Any unbalanced or parasitic mass in the rotor willV induce impulse in the bed member 2 which, by virtue of the nature and disposition of the the frame of the bed member 2, will indicate the oscillations of the latter and the amplitude or degree of vibration set up by the unbalanced mass of the rotor, thus indicating the de ee of unbalance, which is compensated gdr by the temporary application of balancing weights to counteract or oiset the unbalance, in accordance with a familial'v practice. y

When one end of the rotor has been balanced--in this manner, as indicated by the absence of.oscillatory motion in the bed, the oscillation axis is shifted to the other transverseplane about which a test for balance is to be made, by adjusting the spring elements as heretofore explained; and the balancing operationis repeated for the other end of the rotor.

When the rotor has been fully balanced, permanent correction weights may be applied or material removed either while the rotor is onthe machine hedor after it is removed to a more convenient location: v

. Instead of adjustin the spring members 4 Y venient to retain a permanent setting of the spring elements and shift the pedestal journals 5, which support the rotor to be tested', on the bed member 2 in ,a longitudinal direc- 'tion. This procedure Will be just as effective as the adjusting of the spring elements theming operation.

It is evident from the foregoing description of my invention that balancing machines, for dynamically balancing rotors yand the like, made in accordance therewith provide simple and effective means for testing rotors of i Althour any size and shape in an eliicient and in expensive manner, and that by virtue of their simplicity, such machines may be constructed at a relatively low proportion of the cost of the more intricate and -complex machinery heretofore' roposed.

g I have described a specific embodiment of my invention, it will be obvious to those skilled in the art that various modifications maybe made in the details of conied therein, Without departing from the principles herein set forth.

I claim as my invention:

a bed member carried b said base, a plurality of flexible elements isposed intermediate said base and bed, means for journalling a rotor to be tested on said bed, and means for actuating said rotor-t0 rotate the same, the

relative `disposition of said exible elements being adapted'to permit an oscillatory movement of said bed about a. predetermined axis perpendicular to the base.

. 2. A balancing machine comprising a base, abed member carried by said base, aplural- Y ity of flexible elements disposed intermediate said base and bed,'means for journalling a rotor to-be tested on said bed, and means for actuating said rotor to rotate the same, the relative disposition of said flexible elements being adapted to permit an oscillatory movement of said bed about a predetermined vertical axis.

3. A balancing machine comprising a base, a bed member carried by said base, a plurality of angularly adjustable iiexible elementsv disposed intermediate said base and bed, means for journalling a rotor to be tested on said bed, and means for actuatingA said rotor to rotate the same, the relative disposition of said flexible elements being adapted to permit an oscillatory movement of said bed about an axis determined by the intersection of the mainv planes of said flexible elements.

4, A balancing machine comprising a base,

a bed member carried thereby, a pluralit Y of liat spring elements disposed interme iate said base and bed, said springs being adjustable Vto cause their lon itudinal planes extending parallel to their at faces to converge lto determine a rotation axis, means for journalling a rotor to be tested on said bed, means for actuating said rotor to rotate the same, and means comprising said spring elements for restraining movement of said bed in all directions except substantially t'angentially to said axis.

5. A balancing machine comprising a base a bed member. carried thereby, a plurality of fiat spring elements disposed intermediate said base and bed, said springs being adjustable to cause their longitudinal planes extending parallel to their fiat faces to converge to determine a rotation axis, means for journalling a rotor to be tested on said bed, means for actuating 'said rotor to rotate the same, indicatingl means for ascertaining the degree of movement of said bed, and means comprising said spring elements for restraining movement of said bed in all directions except substantially tangentially to said axis.

6. An oscillating systemv for a balancing machine comprising a base, a plurality of leaf springs mounted perpendicular to the base and a bed member carried by the leaf springs, said leaf springs being disposed to be adjusted to lie in planes that radiate from l anyl predetermined axis of oscillation. 1. A .balancing machine comprising a base,

7. A spring system comprising a' plurality of flexible beams that are disposed to be adjusted in such manner that the planes containing the neutral axes of the beams may be caused to intersect in any line that is parallel to all of said planes.

8. In a balancing machine, the combination with a supporting base, of a plurality of leaf springs mounted perpendicular on said base and disposed to be adjusted to lie in planes that intersect at a common axis, and a vibrating bed mounted on the leaf springs.

9. A balancing machine comprising a base,

a pluralityof leaf-spring members mounted;

vertically on the base and a -bed member mounted( on the leaf-spring members for os- ,l

spring members being disposed to be turned so that theplanes occupied by\their neutral axes will intersect in any predetermined line parallel to said planes to constitute the axis of oscillation of the balancing machine.

11. A balancing machine comprising a base, a bed member carried by the base and a plurality of iexible elements disposed between the base and the bed member, said flexible elements being disposed to be adjusted to permit the bed member to oscillate relative to the v base inV a horizontal plane about a. vertioal 's axis in any position.

In testimony whereof, I have hereunto sublscribed my name this 6th day of August 1925.

WILLIAM E. TRUMPLER. 

